Many applications of diode lasers and LEDs involve the columnation of or focusing of the emitted optical signal and measurement of a return signal along the optical axis of the outgoing signal. Examples of such systems include magneto-optical, CD-ROM, and DVD computer mass storage devices wherein a diode laser is focused onto a spot on the recording media and a reflected signal is measured.
Prior art optics for such systems conventionally include a plurality of separate optical elements through which the laser light must pass. It is not untypical for the laser light to pass through eight or more separate optical surfaces prior to arriving at the storage media and six or more additional surfaces before arriving at a photodetector. Significant optical losses and degradation of signal quality occur due to optical signal passage through these surfaces. Alignment of the laser and the optical elements employed is critical and misalignment can and does occur on an all too frequent basis.
In duplex fiber optic communication systems employing diode lasers or LEDs the optical couplers employed cause significant loss of optical signal, often resulting in a small percentage of the emitter energy arriving at the photodetector employed in such systems. This is true regardless of the type of emitter-to-fiber couplers employed in prior arrangements, including for example, cylindrical lenses, butt contact, spherical ball couplers, and aspheric lenses.
The following United States patents and publication disclose systems believed representative of the current state of the prior art: U.S. Pat. No. 5,644,563, issued Jul. 1, 1997, U.S. Pat. No. 5,701,287, issued Dec. 23, 1997, U.S. Pat. No. 5,406,543, issued Apr. 11, 1995, U.S. Pat. No. 5,621,714, issued Apr. 15, 1997, U.S. Pat. No. 5,467,336, issued Nov. 14, 1995, U.S. Pat. No. 5,010,822, issued Apr. 30, 1991, U.S. Pat. No. 5,650,874, issued Jul. 22, 1997, U.S. Pat. No. 5,124,841, issued Jun. 23, 1992, U.S. Pat. No. 5,646,928, issued Jul. 8, 1997, U.S. Pat. No. 4,917,014, issued April, 1990, U.S. Pat. No. 5,323,378, issued June, 1994, U.S. Pat. No. 5,708,644, issued January, 1998, and The Laser Guide Book, Hecht, J., Page 331, McGraw-Hill, 1992.